The present invention relates generally to an improved sharpener and, more specifically to an inexpensive pencil sharpener adapted to be carried by, and/or slidingly grip any standard non-mechanical pencil to be sharpened so as to be readily available for immediate use at any time.
Pencils have been around for centuries, and methods and apparatuses for sharpening pencils have been in the art for nearly as long as pencils themselves. Most non-mechanical pencils have a fungible outer core or sheath surrounding a graphite inner core. Alternatively, the inner core may be comprised of any material such as wax or the like that leaves a desired mark when pressure is applied.
One problem with non-mechanical pencils and their sharpeners is a frequent lack of availability of the sharpener when and as needed. In the prior art, sharpeners are separate from the pencil. Most often, modern sharpeners are stationary, having a base which is often designed to be more or less permanently mounted, or large units with a base such as a motorized sharpener. As such, these devices are not easily transported, and are kept apart from the pencil to be sharpened. Other smaller pencil sharpeners are non-mounted and are small enough to be easily carried but, due in some part to their small size, tend to be easily lost or forgotten and so are often not available when desired. It requires considerable user-diligence to continually carry around a small portable sharpener so that the sharpener is available when needed.
In the prior art, pencils are inserted with a sharpening mechanism which, as noted above, must first be located by the user prior to sharpening. One usual form of pencil sharpeners comprises a pair of cylindrical rollers having a plurality of helical cutting surfaces formed along the longitudinal periphery of each roller. The long axis of each roller is positioned at an angle with respect to a longitudinal sharpening axis about which the rollers both rotate in a manner such that each roller turns about its own axis counter-rotatively with respect to the other roller as both rollers rotate about the sharpening axis. A pencil inserted at a divergent open end of the inclined rollers has a point formed thereon as it is urged towards the converging end of the rollers. This type of sharpener typically requires mounting, is relatively expensive, and is not easily transported due to bulkiness.
Another usual form of pencil sharpeners has a cutting surface located at least partially exposed to in inner channel where the inner channel is adapted to receive a pencil or a tip of the pencil to be sharpened. For example U.S. Pat. No. D420,390 issued to Donaldson is typical.
Other prior art includes pencils with specially adapted sharpeners. U.S. Pat. No. 5,957,602 issued to Rosenthal is typical and discloses a wax pencil holding device formed from a main body. The main body is formed from first and second tubular portions. A thin wax pencil is adapted to be removably received within the first tubular portion of the main body. The wax pencil is dispensed and retracted via a sliding plunger. The wax pencil further includes a pencil sharpener with a frusto-conical inset portion. The pencil sharpener is removably coupled to the first end of the second tubular portion. A shaving container is included for storing the shavings of the wax pencil. The shaving container is adapted to be removably coupled to the second end of the pencil sharpener.
U.S. Pat. No. 5,894,669 issued to Luttgens is also illustrative. Luttgens ""669 teaches a pencil sharpener for a soft core pencil that includes a sharpener housing defining a guide channel, adapted to receive a front region of the pencil therein and conically tapering in an insertion direction of the pencil, and a free space adjoining the guide channel in the insertion direction being adapted to receive a core tip of the pencil therein. The sharpener further includes a sharpener blade disposed within the housing and is positioned tangentially with respect to the guide channel, and a housing projection disposed in the housing and projecting into the free space and being configured for shaping the core tip of the pencil according to an intended shape. The housing projection comprises a shaving rib having an approximately wedge shaped cross section and projecting from the housing projection in an effective direction essentially tangential to a circumference of the core tip and being configured as a generator for the intended shape of the core tip.
Another common form of pencil sharpener is a motorized sharpener such as U.S. Pat. No. 4,601,316 issued to Verdi.
The prior art discussed above does not provide a readily available pencil sharpener that may be readily and easily clipped to and utilized with any pencil or other device which requires sharpening. Consequently, there remains a need to provide a low-cost, pencil sharpener that may be conveniently mounted and transferred to any pencil such that a pencil sharpener is always available.
Accordingly, it is an objective of the present invention to provide an improved pencil sharpener appropriate for non-mechanical pencils.
Another object of the present invention is an improved sharpener also suited for use as a stake sharpener or for sharpening other objects with adaptation to the desired size.
Yet another object of the present invention is a readily available, low cost sharpener that may be quickly and easily mounted to a pencil.
Accordingly, an improved pencil sharpener is described.
The present invention provides a pencil sharpener slidably mountable to a pencil and preferably comprises elements such as, for instance, a first arm adapted to receive a cutting blade, a second arm pivotally mounted with respect to the first arm, the first arm and the second arm defining there between an aperture for receiving the pencil, a biasing member for biasing the first arm pivotally outwardly with respect to the second arm, and stop members to limit the pivotally outwardly movement of the first arm with respect to second arm.
In one embodiment, the pencil sharpener may comprise a pencil bounding surface defined between the first arm and the second arm when the first arm and the second arm are compressed for pivotally inwardly movement with respect to each other, the pencil bounding surface engaging the end of the pencil to be sharpened thereby providing a boundary for limiting axial movement of the pencil with respect to the cutting blade during sharpening of the pencil.
Other elements may include stop members to limit the pivotally inwardly movement of the first arm with respect to the second arm and/or a housing whereby the first arm and the second arm being pivotally mounted within the housing for pivotal movement with respect to the housing. The first arm and/or second arm may define a channel therein for receiving cuttings produced during sharpening of the pencil.
Additional elements may include an axial position gripping surface such that the axial position gripping surface is engageable with the pencil for affixing the pencil to an axial position at any position along an axial length of the pencil. In one embodiment the axial position gripping surface comprises a grommet and/or a first interior surface of the first arm and a second interior surface of the second arm whereby the biasing member urges the first interior surface and the second interior surface into engagement with the pencil.
In operation, the pencil sharpener provides a method which may include steps such as, for instance, inserting a pencil into the pencil aperture, axially sliding the pencil sharpener along an axial length of the pencil to any position along the axial length of the pencil, and resiliently affixing the pencil sharpener at the axial position along the axial length of the pencil sharpener.
Other method steps may comprise axially sliding the improved pencil sharpener along the pencil from the axial position to a position proximate a pencil tip to be sharpened, bringing a cutting edge of the pencil sharpener into contact with the pencil tip, rotating the pencil tip until a desired cut is achieved axially sliding the pencil sharpener back along the pencil, and automatically affixing the pencil sharpener to the pencil. In a preferred embodiment, the method may comprise bringing a cutting edge of the pencil sharpener into contact with the pencil tip by compressing the plurality of arms. The step of resiliently affixing may comprise compressing a grommet.
A method of making a pencil sharpener in accord with the present invention may comprise steps such as, for instance, pivotally interconnecting a plurality of arms such that the arms are pivotal inwardly and outwardly with respect to each other, providing a pencil receiving aperture through the plurality arms with a variable-sized opening therethrough, the variable size opening varying in size due to movement of the plurality of arms pivotally inwardly and outwardly, and mounting a cutting blade to at least one of the plurality of arms.
Other steps may include providing that an interior surface of the plurality arms form a conical surface for engaging a pencil tip end of the pencil when the plurality of arms are moved pivotally inwardly with respect to each other and/or biasing the plurality of arms pivotally outwardly with respect to each other and/or mounting the plurality of arms in a housing and/or mounting a grommet within the pencil receiving aperture whereby the grommet has an internal diameter sized to support the pencil sharpener on a pencil by engaging a pencil with a surface of the grommet. In a preferred embodiment, steps may include providing a pivotal connection at an end of each of the plurality of arms and/or forming a radially extending aperture through at least one of the arms to provide an outlet for cuttings formed during sharpening of the pencil.
Thus, an improved pencil sharpener is provided for sliding disposal about a pencil. The pencil sharpener may comprise in one preferred embodiment one or more of the following elements such as a cutting surface, a first arm having a first end, a second end, a top end, a bottom end, a first side having a first pivot disposed outwardly near the second end, and a second side having a second pivot disposed outwardly near the second end, the bottom end having a substantially semi-frusto-conical channel therethrough, the first arm further adapted to receive the cutting blade, and a second arm having a first end, a second end, a top end, a bottom end, a first side having an aperture disposed near the second end for accepting the first pivot, and a second side having an aperture disposed near the second end for accepting the second pivot, the top end having a substantially semi-frusto-conical channel therethrough, wherein the pivot may be disposed within the pivot channel of the first arm and the pivot channel of the second arm, whereby the first arm pivots with respect to the second arm into a first open position and second closed posit-ion, the semi-frusto-conical channel of the first arm and the semi-frusto-conical channel of the second arm form a substantially frusto-conical channel and a substantially cylindrical channel in the second closed position, whereby the pencil sharpener accepts the pencil therethrough and remains substantially stationary about the pencil in the first open position and slidingly engages the pencil in the second closed position and/or the cutting surface engages the pencil in the second closed position and does not engage the pencil in the first open position.